Can you helicopter a paladin into jungle combat?
NO!
But, can a 155 take small arms fire and keep up with tanks?
NO!
In 'Nam, we just helicoptered 155s into position.
In Iraq, paladins supported armor.

The towed 155 can be airlifted by a Blackhawk. Check out http://www.globalsecurity.org/military/library/policy/army/toe/
You will find that light infantry divisions will have towed 155's and heavy formations such as Mech Infantry, Armored Divisions, etc. have Paladins.
Marine formations are always light, so they use towed artillery.
Texastillidie